This semester Will Russack, A14, enrolled in the “Environmental Preservation and Improvement” course taught by Associate Professor George Ellmore. The course’s goal is to “energize students’ desire to work for positive and measurable environmental change” by highlighting solutions to current environmental problems.

Little did Russack know, the two-and-a-half hour environmental studies seminar would inspire him to write a series of posts on his personal blog on the topics discussed in class. He writes: “So far I’m really enjoying the class because every week I come away with a plethora of knowledge about a new topic and the confidence to talk about it.”

One of those topics was “colony collapse disorder,” the phenomenon of the sudden disappearance of honey bees in the United States:

“We investigated the potential for multiple factors to be working together to create these massive die-offs, as the research has been unable to find a clear culprit. The first factor discussed is the usage of systemic pesticides. Systemic pesticides spread throughout all the tissues of a plant, including the nectar and pollen. This means that adult forager bees are receiving direct exposure to the pesticides, and that entire colonies are experiencing indirect exposure when the foragers return. Systemic pesticides are known as neonicotinoids, which have been shown to have significant effects on the central nervous system.

A study by Pettis et al. demonstrated that honey bees exposed to a systemic pesticide known as imidacloprid were significantly more susceptible to infection from the gut pathogen Nosema (figure 1). A second study by Henry et al. showed that exposure to systemic pesticides decreased foraging success in honey bees. The bees were fitted with radar tagging devices to track their position (figure 2). The bees experienced significant“homing failure,”  with up to 31% of bees exposed to pesticides unable to find their way back to hive after foraging. Mortality due to homing failure was even higher when the bees were unfamiliar with their foraging area, as one would expect. Here we can see how just 1 factor, pesticides, is able to have multiple effects on bee health and how these factors could interact to weaken colonies.”

For more on Russack’s presentation, check out his blog post.